Myth: Soyfoods have feminizing effects on men.
Fact: Soyfoods do not feminize men or impair male fertility.
Extensive clinical research shows that even large amounts of soy do not lower testosterone levels or raise estrogen levels in men. Clinical research also shows that soy does not adversely affect sperm or semen parameters. In fact, Italian researchers suggested soy isoflavones could be a treatment for low sperm count.
Messina M. Soybean isoflavone exposure does not have feminizing effects on men: a critical examination of the clinical evidence. Fertil Steril 2010;93:2095-104.
Casini ML, Gerli S, Unfer V. An infertile couple suffering from oligospermia by partial sperm maturation arrest: can phytoestrogens play a therapeutic role? A case report study. Gynecol